InkyPHAT B&W version incorrect response to "colour" flag

Hi everyone. Having just purchased and installed a black & white InkyPHAT, I’m coming across an unusual problem. None of the examples work with the colour attribute set, e.g.

python3 --colour "black"

The screen fails to update. If I remove the colour flag, the examples function correctly. These might not seem a problem, but I have some 3rd party code that used a red InkyPHAT that I’m trying to adapt. However, there seems a dependency on the colour being set in the listing, which I have been trying to remove without success (a “” is not accepted):

inky_display = InkyPHAT(colour)
scale_size = 1
padding = 0

img ="P", (inky_display.WIDTH, inky_display.HEIGHT))
draw = ImageDraw.Draw(img)

font = ImageFont.truetype(HankenGroteskMedium, 18)
results = = 23424975)

trends_string = ""

for location in results:
    for trend in location["trends"][0:5]:
        trends_string += " - %s" % trend["name"] + "\n"

w, h = font.getsize("Hello, World!")
x = 0
y = 0

draw.text((x, y), trends_string, inky_display.RED, font)

Can anyone help?